Since I have a large vocabulary and deal with early music and old literature a lot, I have seen some spellcheck suggestions that were real doozies. I smile, but I then forget them.

My spellchecker has the weakness of not recognizing things like 1st, 2nd, 3rd, etc.

Finally I sent my sweetie an e-mail with the subject "ignore this e-mail" and I sent and spellchecked expressions from 1 - 31 plus a few more (50th, 75th, umpteenth) so that I would never have to okay them again.